The document provides an overview of lasers in dentistry, including:
1. A definition of lasers and their key characteristics of being monochromatic, coherent, and directional.
2. A brief history of lasers from early phototherapy research to the invention of the laser in 1960.
3. Descriptions of common dental laser types like CO2, Er:YAG, and Nd:YAG lasers and their applications like soft tissue surgery.
4. Advantages of lasers include reduced bleeding, less need for sutures, and faster surgery times.
Lasers in dentistry (2)/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Lasers in dentistry1/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Lasers in dentistry/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Light is an integral part of our life. Advances in technology are increasing and changing the ways that the patient experience dental treatment. One of the milestones in technological advancements in dentistry is the use of lasers The early 20th century saw one of the greatest inventions in science & technology, in that LASERS which later went on to became a gift to health sciences. Albert Einstein is usually credited for the development of the laser theory. He was the first one to coin the term “Stimulated Emission” in his publication “Zur Quantentheorie der Strahlung”, published in 1917 in the “Physikalische Zeitschrift”
Lasers are devices that produce beams of coherent and very high intensity light. The word LASER is an acronym for “Light Amplification by Stimulated\Emission of Radiation”. A crystal or gas is excited to emit light photons of a characteristic wavelength that are amplified and filtered to make a coherent light beam. The effect of the laser depends upon the power of the beam and the extent to which the beam absorbed. Several types of lasers are available based on the wavelengths. These range from long wavelengths (infrared), to visible wavelengths, to short wavelengths (ultraviolet), to special ultraviolet lasers called excimers. Lasers are used nowadays in many areas in the field of dentistry It is of the most captivating technologies in dental practice. Even though, introduced as an alternative to the traditional halogen curing light, laser now has become the instrument of choice, in many dental applications. Its advancements in the field of dentistry are playing a major role in patient care and well being.
Lasers in dentistry (2)/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
The Indian Dental Academy is the Leader in continuing dental education , training dentists in all aspects of dentistry and
offering a wide range of dental certified courses in different formats.
Lasers in dentistry1/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Lasers in dentistry/ orthodontic course by indian dental academyIndian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Light is an integral part of our life. Advances in technology are increasing and changing the ways that the patient experience dental treatment. One of the milestones in technological advancements in dentistry is the use of lasers The early 20th century saw one of the greatest inventions in science & technology, in that LASERS which later went on to became a gift to health sciences. Albert Einstein is usually credited for the development of the laser theory. He was the first one to coin the term “Stimulated Emission” in his publication “Zur Quantentheorie der Strahlung”, published in 1917 in the “Physikalische Zeitschrift”
Lasers are devices that produce beams of coherent and very high intensity light. The word LASER is an acronym for “Light Amplification by Stimulated\Emission of Radiation”. A crystal or gas is excited to emit light photons of a characteristic wavelength that are amplified and filtered to make a coherent light beam. The effect of the laser depends upon the power of the beam and the extent to which the beam absorbed. Several types of lasers are available based on the wavelengths. These range from long wavelengths (infrared), to visible wavelengths, to short wavelengths (ultraviolet), to special ultraviolet lasers called excimers. Lasers are used nowadays in many areas in the field of dentistry It is of the most captivating technologies in dental practice. Even though, introduced as an alternative to the traditional halogen curing light, laser now has become the instrument of choice, in many dental applications. Its advancements in the field of dentistry are playing a major role in patient care and well being.
Lasers in ophthalmology - Dr. Parag Apteparag apte
A full presentation of one hour of all types of lasers in ophthalmology for under graduates and post graduates after going through all the uploaded slides till today. This includes laser photocoagulation, laser iridotomy, and laser capsulotomy in detail
PRESENTATION 4- Basics of Laser in Dermatolgy
It includes -
Laser spectrum
Definition Laser
Classification of Lasers
Laser Theories
Laser terminology
Laser Hazards
Lasers in oral & maxillofacial surgery/oral surgery courses by indian dental ...Indian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Basics refresher on Laser Technology and it's applications. Presentation prepared by (and for) student(s). Level- Karnataka State Pre-university PUC1(India)
Characteristic of light
History
Laser physics and properties
Component of laser
Classification of laser
Biological effect of laser
Laser effect on dental tissues
Laser safety in dental practice
General application of laser
Personal protective equipment
Types of laser intensity in orthodontics
Uses of laser in orthodontics
Effect of laser in orthodontics
Lasers in ophthalmology - Dr. Parag Apteparag apte
A full presentation of one hour of all types of lasers in ophthalmology for under graduates and post graduates after going through all the uploaded slides till today. This includes laser photocoagulation, laser iridotomy, and laser capsulotomy in detail
PRESENTATION 4- Basics of Laser in Dermatolgy
It includes -
Laser spectrum
Definition Laser
Classification of Lasers
Laser Theories
Laser terminology
Laser Hazards
Lasers in oral & maxillofacial surgery/oral surgery courses by indian dental ...Indian dental academy
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Basics refresher on Laser Technology and it's applications. Presentation prepared by (and for) student(s). Level- Karnataka State Pre-university PUC1(India)
Characteristic of light
History
Laser physics and properties
Component of laser
Classification of laser
Biological effect of laser
Laser effect on dental tissues
Laser safety in dental practice
General application of laser
Personal protective equipment
Types of laser intensity in orthodontics
Uses of laser in orthodontics
Effect of laser in orthodontics
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stockrebeccabio
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stock
Telegram: bmksupplier
signal: +85264872720
threema: TUD4A6YC
You can contact me on Telegram or Threema
Communicate promptly and reply
Free of customs clearance, Double Clearance 100% pass delivery to USA, Canada, Spain, Germany, Netherland, Poland, Italy, Sweden, UK, Czech Republic, Australia, Mexico, Russia, Ukraine, Kazakhstan.Door to door service
Hot Selling Organic intermediates
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
2. outline
•Definition
•The invention of laser
•Laser components
•Fundamental of laser
•Designs
•Basic principles
•Types of dental laser
•Applications
•Advantages
•Early dental laser research •Disadvantages
•Laser hazards
•Limitations
3. INTRODUCTION
• The word "laser" is an acronym for
Light
Amplification
by the
Stimulated
Emission
of
Radiation
• A device that creates a uniform and coherent light that is very
different from an ordinary light bulb.
4. • The use of light for t/t of various pathology:“PHOTOTHERAPY”
• In 1903, a Danish physician named Niels Finsen developed a
technique known as carbon arc phototherapy – t/t of lupus
vulgaris.
• The first laser was developed by Theodore H. maiman in1960.
• MASER – microwave amplification by stimulated emission of
radiation, 1st reported in 1958 by Schawlaw and
Townes.
5.
6. L stands for Light.
•
•
•
Monochromatic.
– one specific wavelength of light (one specific color).
– The wavelength of light is determined by the amount of
energy released when the electron drops to a lower orbit.
Coherent
– “organized” -- each photon moves in step with the others.
This means that all of the photons have identical wavelength
and frequency .
Very directional
- A laser light has a very tight beam and is very strong and
concentrated and focused i.e. collimated
7.
8. • These characteristics are very different from light from a
lightbulb.
• Lightbulb light:
– has many colors mixed together
– doesn't come in a narrow beam
– cannot be focused to as small a spot
– cannot be as intense as a laser without expending
tremendous amounts of energy.
• Lasers are special because they allow us to control light in
new and important ways.
9. A in laser stands for amplification
• Amplification means that a very bright intense beam of light can
be created.
• The laser may be activated by a few photons,
but then many, many more are generated.
• The initial light is amplified to make a very
bright compact beam.
10. S in laser stands for stimulated
• Stimulated means that the photons are amplified by stimulating
an atom to release more photons.
• An atom can exist in an excited state,
similar to a bow when it is stretched.
When the atom relaxes it emits a photon.
11. •
•
•
•
E in laser stands for emission
Emission refers to the giving off of photons.
The excited atom emits a photon when another photon comes
by.
In 1917, Einstein described this process as Stimulated
Emission.
The photons bounce between
the two mirrors until enough
photons have been emitted,
some pass through the
semi-silvered mirror on one end,
which are seen as the laser
beam.
12. R in laser stands for radiation
•
•
It is a general term for anything that is radiated, or given off by
an object.
For lasers, radiation refers to the photons which are being
emitted.
14. EARLY DENTAL LASER RESEARCH
• Dental research began in 1963 at university of California at Los
angeles school of dentistry, with investigators Stern and
Sognnaes.
• RUBY LASER:
- 1st laser constructed by Maiman
- Emitted light of 0.694µm.
- reported :
- development of cratering and glass like fusion of enamel
- penetration and charring of dentin(500-
2000J/cm²) (Stern, 1964)
15. • In 1974, Stern observed resistance to acid penetration into
enamel, suggesting role of laser in caries prevention.
• In 1965 – Taylor and Associates reported extensive
hemorrhagic necrosis and disruption of odontoblastic layer .
• CO2 laser: 1970
- more effective for hard tissues as its wavelength of 10,600 nm
is well absorbed by enamel.
High affinity for hydroxyapatite
- In 1984, Melcer et al reported successful t/t over 1,000
patients in clinical trails of caries removal and in1987,concluded
that laser could induce secondary dentin formation and
sterilization of dentin and exposed pulp.
16. • Neodymium laser:
- 1974, Yamamoto and Ooya in Japan
- Determined as an effective tool for inhibiting the
formation of incipient caries both in vivo and vitro.
•In 1995 FDA cleared a laser device for gingival surgery
•On may 7, 1997 FDA cleared the use of laser in treatment of tooth
decay and in 1998 October , given clearance for use in children
17. LASER COMPONENTS
• An optical cavity:
- 2 parallel mirror placed on either side
- Mirror(M1) is totally reflective and other Mirror(M2) partially transmissive
- photon bounce off the mirrors and re-enter the medium to
stimulate the release of electrons
• Laser medium:
- suspended as a gas, a liquid, a solid sate
- homogenous population of atoms or molecules pumped
up to the excited state
•
•
A pump energy source
Cooling system
18. BASIC PARTS OF A LASER
DEVICE
• The laser production device has the following parts:
1. Optical cavity: in which all the other components of laser
are housed
2. Active medium: the main component present in the core of
the optical cavity which helps in the production of light
3. External energy source: A flash lamp or electric arc device
4. Optical mirrors: one totally reflective and one partially
transmissive mirror
5. Optical resonator: Helps to prevent the scattering of
radiation in the optical cavity
6. Lens: helps in convergence of the light to a focal point.
19.
20. LASER DELIVERY SYSTEM
• 2 delivery system
• hollow guide or tube
• flexible glass fiberoptic cable
– fragile and can not be bent sharply
– Various sizes of diameter
– Encased in resilient sheath
– Fit into hand piece with bare end or attached
glass like tip
21. • Laser action is explained by the theories of
quantum mechanics and thermodynamics
• Postulated by Danish physicist Bohr
22.
23.
24.
25. Fundamental of laser
• To make the laser work, the material is excited or "pumped,"
with light or electricity.
The pumping excites the electrons in the atoms, causing them
to jump to higher orbits
"population inversion."
• Few of the electrons drop back
to lower energy levels spontaneously,
releasing a photon (quantum of light).
26. 1.High-voltage electricity causes
the quartz flash tube to emit an
intense burst of
light,exciting
some
of the
atoms
in the ruby crystal to
higher energy levels.
27. 2. At a specific energy level, some atoms
emit particles of light called photons. At f
irst the photons are emitted in all directio
ns. Photons from one atom
stimulate emission
of photons
from
other
atoms
and the
light intensity is rapidly
amplified.
28. 3. Mirrors at each end reflect the photons
back and forth, continuing this process
of stimulated emission
and amplification.
29. 4. The photons leave through the partially
silvered mirror
at one end.
This is laser
light.
30. Mode of light emission
•
•
• Continuous wave:
-beam emission is at one power level continuously as long
as the device is activated.
Gated-pulse mode:
-periodic alteration of the laser energy being on and off
( few milliseconds)
Free running pulse mode:
- large peak laser energy emitted for an extremely short time
span (µs) followed by long time laser off
32. 1. According to ANSI and OSHA standardization
Class I: Low powered lasers which are safe to view by the
naked human eye. Eg. Laser pointer device
Class II a: Low powered lasers which are hazardous if
viewed for more than 1000seconds by the naked eye. Eg
He:Ne lasers.
Class II b: Low powered visible lasers that are hazardous if
viewed for more than 0.25 seconds.
Class III a: Medium powered lasers that are normally
hazardous if viewed for more than 0.25 seconds without
the use of magnifying optics.
Class III b: Medium powered lasers (0.5 W max.) which are
hazardous if viewed directly.
Class IV: High powered lasers (> 0.5 W) which produce
ocular, skin and fire hazards.
33. 2. Based on wavelength:
Ultraviolet lasers (140- 350nm)
Visible lasers (350-750nm)
Infra red lasers (750nm and above)
3: Based on penetration power:
I-- Hard lasers/ Thermic lasers/ Surgical lasers
II-- Soft lasers/ Athermic lasers
4. Based on pulsing as:
I--Pulsed lasers
II--Non pulsed lasers
34. 5. Based on the type of active medium used:
Gas lasers: a gas or mixture of gases is used as
active medium Eg: He: Ne lasers, CO2 laser
Liquid lasers: Ions of rare earth or organic
fluorescent dye dissolved in liquid are used as
active medium. Eg: Dylase
Solid state lasers: Solid material are used as
active medium eg: Ruby lasers, Nd:YAG lasers.
Semiconductor lasers: Semiconductor materials
are used as active medium. Eg: Gallium
-arsenide laser
35. STATE MEDIUM
CO2 ,Nitrogen, Helium gases
Gas- CO2 , Argon laser
Solid state-
Nd:YAG
Er:YAG
Ho:YAG
Semiconductor- Diode laser
Yttrium, Aluminium, Garnet
crystals ( Neodymium,
Ergium, Holmium)
semiconductor chips work
like electrode
- layer of p-type material (carrier of
+ve charge or electron holes), a
nonconductive band gap layer
(junction), a layer of n-type material
( carrier of –ve charge or free
electrons.)
36. Most commonly used Lasers in dentistry
CO2
Er:YAG(erbium-doped yttrium aluminium garnet)
Nd:YAG(neodymium-doped yttrium aluminium garnet)
Diode
Argon
38. • First laser used routinely for
soft tissue surgery in dentistry.
• Since the human body contains about 85 % water and the
value for soft tissue is even higher, the CO2 laser will be
absorbed in the water part of all soft tissues.
• Wavelength-10,600nm
• Deliver through a hollow tube like wave guide in continuous or
gated pulse mode
39. suitable for application of teeth
•
•
•
•
sealing of pits and fissures
welding of ceramic material to enamel
prevention of dental caries
Used in non contact manner for tissue ablation
heat diffusion and heat accumulation occurs.
coagulation of small blood vessels in the depth of the tissue
prevents bleeding from those vessels
40. Irritation fibroma on buccal
mucosa
Excisional biopsy with co2 laser
Underlying surface dry, no suture placed 6 wks after surgery
41. Maxillary midline frenum causing
pull on marginal and interdental
papillae.
Immediately after co2 lasing, the
char layer and lack of suture
2mnths after surgery
42. Advantages of the CO2 laser
• less or no bleeding, resulting in a dry
surgical field
• reduction of surgical time due to better
visibility
• reduced swelling
• reduced pain due to the fact that
superficial nerve endings are
coagulated
• less or no sutures, resulting in shorter
treatment time
• less scaring.
It was reported the use of the CO2 laser was unfavourable
because of the loss of the odontoblastic layer (Wigdor et
al., 1993)
43. • Wavelength-2940nm( coincides with the absorption
peak of water)
Excellent absorption in apatite crystals and water
• With Er:YAG laser, minimal thermal damage to
dentin seen, and removed infected and softened
carious dentin to the same degree as the
bur treatment.
• The advantage of these lasers for soft tissue is that, with
very high absorption by water, only a few layers of
tissue are removed with each pulse of laser energy, so
removal and reshaping can proceed with precision
44. APPLICATION
• Caries detection and removal
• Removal of dental fillings
( composite and GIC )
Amalgam Χ – potential release of mercury vapour
• Removal of gold and ceramic fillings – not possible
• Apiectomy, osteotomy of bone, impacted teeth – excellent bone
healing capacity.
• Laser irradiation adjacent to pulp
local damage occurs = mechanical injury by burs.
45. •
•
•
Caries prevention :
Laboratory studies shown laser t/t of enamel can inhibit
caries progression by 50%.
One time laser t/t = daily fluoride t/t
• laser irradiation of dental hard tissues modifies the
calcium to phosphate ratio, reduces carbonate to
phosphorous ratio, and leads to the formation of more
stable and less acid soluble compounds.
• Threshold pH for enamel dissolution was reportedly
lowered from 5.5 to 4.8 and the hard tooth structure was
four times more resistance to acid dissolution.
46. •
•
•
•
•
•
Wavelength-1045nm
Solid medium, a crystal of yttrium- aluminum and garnet
doped with neodymium
readily absorbed in blood and tissue pigment
These instruments are ideal both for the treatment of
periodontitis and for excisions of vascularized lesions
(excellent hemostatic ability).
Their energy is transmitted through water, and are very
minimally interactive with hard tissue
Applications similar.
47. BDJ, VOL 187, 1999
- Laser soft tissue surgery was well accepted by child patients.
- The Nd:YAG laser is a very useful additional clinical tool for dentists treating
children.
48. •
•
•
•
•
•
•
A crystal of yttrium-aluminum garnet doped with holmium
Wave length- 2120 nm
High affinity to H2O absorption by soft tissues
Useful for soft tissue excision
Less affinity for pigmented tissue and tooth structure
Frequently used for arthroscopy in TMJ
Compared to CO2 Laser – Ho:YAG offers better
homeostasis and is safe and effective to use bone and
cartilage.
49. PPorortatabbllee
No special power
No cooling connection
No heat
Quiet
AAfforfforddababllee
More powerful, less traumatic
wavelenght-800-980nm, invisible
Well absorbed by soft tissue and poorly absorbed by
hard tissues
ExExppananddPPrracacttiiccee
•Gingival contouring
•Sulcular debridement
PPorortatabbllee
No special power
No cooling connection
No heat
Quiet
AAfforfforddababllee
More powerful, less traumatic
wavelenght-800-980nm, invisible
Well absorbed by soft tissue and poorly absorbed by
hard tissues
ExExppananddPPrracacttiiccee
DIAODE LASER
SEMICONDUCTOR LASER change
electric energy to light energy
Gallium Arsenide chip and Al
Delivery system-fibroptically in
continuous wave or gated pulse
Portable
No special power
No cooling connection
No heat
Quiet
Affordable
More powerful, less traumatic
wavelength-800-980nm, invisible
Well absorbed by soft tissue and poorly
absorbed by hard tissues
50. • Wavelength - 488nm and 514nm
peak absorption in red pigments and tissues with abundance
Hb, hemosiderin and melanin.
• Enamel and dentin – not well absorbed, poorly absorbed by
water.
• Tissues effects – thermal nature
• Specific uses :
1. Root planning and curettage – photocoagulation
and vaporization of tissues within periodontal pockets.
2.Gingival retraction – excellent homeostasis and
coagulation
51. • creates a tissue temp. 90ºC - 100ºC coagulate the blood
vessels and remove the sulcular epith.
3. Gingivectomy and gingivoplasty
4. Oral lesion therapy: removes the surface epithelium and
necrotic tissues, disinfect the wound
laser is applied until lesion has dessicated appearance
and necrotic cells have glazed appearance.
5. Tissue welding : arterial welding
adv : preserve the mechanical properties of tissues and
decrease hyperplasia
6. Used for curing composite.
52. Lichen planus on buccal
mucosa
Blistering of the tissues by
laser
After blistering lesion
peeled away
Immediately after peeling, a light char
layer, left to heal by secondary intention. 12wks later, postoperatively
53. Labial hemangioma Excision of lesion
Postoperative appearance, complete
hemostasis
2weeks postoperatively, normal
appearance
54. Biolase Waterlaser
• Developed in 1998, October, Doctor Haselhorst
• Uses a process which gently washes away
decay with laser-energized water droplets.
• Hydrokinetic energy is produced by combining
a spray of atomized water with laser energy.
• The result is the energized water gently and precisely
removes a wide range of tissue including tooth enamel, and
soft tissue (gum tissue) with no heat or discomfort in most
cases.
55. • The Waterlase laser does not require being pressed on
to the tooth, so this discomfort is not experienced.
• Modern dentistry now has a dental laser made by
Biolase which allows the dentist to perform certain
procedures without anesthesia.
• Quick and painless
DRILL-LESS
DENTISTRY
56.
57. EXCIMER LASER
•
•
•
•
•
•
It is the only one laser that offers precise ablation of tissues,
fiber delivery, bactericidal effects, good transmission through
water and enamel surface conditioning in one system.
308nm
Very expensive and time consuming
Used for RCT
Temp.elevation within pulp chamber ≤180ºC
Produces opening of dentinal tubules free of smear layer or
necrotic tissues, and allow O2 and medicinal fluids to enter
the tubuli and apical delta.
not possible with conventional procedures.
58. Laser effects in dentistry
Factors which determine the interaction are:
•Wavelength of laser
•Power density
•Difference in delivery system
Tissue factors which determine the effect of laser include:
•Chemical composition
•Spatial structure
•Isotropic composition
Radiant energy interacts with the tissue in 4 different ways:
– A portion may be reflected without any interaction
– A portion may be transmitted
– A portion may be absorbed
– A portion may be absorbed and scattered without
producing any useful effect
63. Reflection
• No effect on target
tissue.
• E.g; caries detecting
laser device.
• Laser beam becomes
more divergent with
increasing distance
from the handpiece.
64. Scattering
• Weakening the
intended energy
• No useful biologic
effect.
• Heat transfer to
adjacent tissue:
unwanted damage.
• One advantage:
facilitate curing of
composite resin or
covering broad area.
66. Transmission
• Depends on the wavelength of laser light
• Depth of beam varies with speed of
movement and power density.
67. Tissue effects can be of 4 types:
•I. Photochemical interaction --- Biostimulation
--- Photodynamic therapy
•II. Photothermal interactions---Photoablation
---Photopyrolysis
•III. Photomechanical interactions---Photodisruption
---Photoaccoustic
•IV. Photoelectrical interactions
Biologic interactions of laser photons with the tissue occurring
along the radiation are termed as linear effects.
Linear effects can be of 3 types --Photochemical, Photothermal
and Photomechanical.
The ability of laser light to produce a biologic response after
being reflected, deflected, scattered or absorbed are called as
non linear effects.
68. Laser effects in dentistry
•
• Oral soft tissue is largely composed of water which
predominantly controls the tissue effects of lasers in the
infrared spectrum.
Tissue elements which exhibit a high coefficient of absorption
for a particular wavelength are called as chromophores. Other
chromophores in the tissue may include hemoglobin, melanin
etc Hemoglobin readily interacts with 488-514nm
wavelengths, thus accounting for the greater ability of argon
laser for coagulation and hemostasis. In soft tissue, the
effects of laser are quiet predictable as compared to hard
tissues.
69. Laser effects in dentistry
•
• Thermal effects:
- 45ºC - 60ºC : Denaturation
- >60ºC : Coagulation and necrosis
- 100ºC : Water inside the tissues vaporizes
- >300ºC :Carbonization and pyrolysis ( muller et al, 1990).
Mechanical effects:
- photoablation
- photodisruption
fast thermal explosion
mechanical shock waves
nonlinear tissue behaviour
optical breakdown
mechanical shock waves
70. • Chemical effects:
- alteration in the chemical and physical properties of the
irradiated tissues
• Laser interaction with living tissues is very complex
mechanism and not yet completely understood.
• Biologic effects of laser on dental tissues depends on a
number of factors
- properties of laser itself ( wavelength, energy density and
pulse duration)
- optical properties of hard tissues.
71. EFECTS ON HARD TISSUES
•
•
•
•
•
•
•
•
Microcracks and zone of necrosis
Carbonization
Cracks on enamel and dentin
Microhardness of dentin increases
Organic matrix burns off
Crystalline structure of HA changes
Transformation of apatite to tricalcium phosphate
Inhibition of enamel subsurface demineralization
prevention of dental caries
(Yamamoto and Ooya , 1974)
72.
73. EFFECTS ON DENTAL PULP
• Recent evidence suggests that a normal odontoblastic layer,
stroma and viable epithelial root sheath can be retained
following laser radiation provided damage threshold energy
densities are not exceeded i.e < 60 J/cm²( Abt el at, 1992)
• If pulp temp > 5ºC , odontoblastic layer may not be present.
• Use of air and water combination before, during or
immediately after laser irradiation may be effective for temp.
control and reduction of heat transfer to the pulp.
• Continous wave – pulpal necrosis, but pulsed mode may
result in new dentin formation ( Melcer et al, 1987)
74. LASER HAZARDS IN DENTAL
PRACTICE
As Martin Strassl said
“Only twice you can make
mistake with Lasers, First
you loss one eye and second
your other”
75. LASER HAZARDS IN DENTAL PRACTICE
• Ocular injury:
- retinal and corneal injury
( 400 – 780nm visible, 780 – 1400 infrared)
• Tissue hazards:
- >21ºC above normal body temp cell destruction and
denaturation of cellular enzymes and proteins
- Happens if by mistake hands come in the way of path of laser
- Should change the laser to the standby mode whenever
interruption in laser use is encountered
76. • Environmental hazards:
- inhalation – resp. system
- Smoke, the byproduct of laser surgery
- Laser plume
– Steam, carbon particles and cellular product
– Contains many toxic substances such as
formaldehyde, hydrogen cyanide
Use of high volume laser smoke evacuation
77. Combustion hazard
•
•
• Flammable solids, liquids and gases within the surgical
settings
Particular concern : flammable gases and endotracheal tubes
due to their proximity during head and neck procedures.
Use of polypropylene surgical gloves/drapes and use of laser
safe endotracheal tubes
Electrical hazards:
• Grouped as electrical shock hazards/ electric fire hazard/
explosion
• Insulated circuitry, shielding, grounding, housing of high
voltage electrical components – adequate protection
78. LASAR HAZARDS CONTROL MEASURE
Recommended by ANSI
• Personal protection
-eyewear ( goggles and
safety glasses, saline
soaked gauze)
- clothing and masks
• Administrative controls
- standard
operative
procedures
- warning signs
- protective devices
- training and education
• •
•
Engineering controls
- equipments label
- key switch
- protective housing
- warning systems
- beam enclosures
Special controls
- fire and explosion
- repair and maintenance
- fibre optic delivery system
79. ADVANTAGES
May cause less pain in some instances, therefore,
reducing the need for anesthesia
May reduce anxiety in patients uncomfortable with the
use of the dental drill
Minimize bleeding and swelling during soft tissue
treatments
May preserve more healthy tooth during cavity removal
80. DISADVANTAGES
Lasers can't be used on teeth with fillings already in place.
Lasers can't be used to fill cavities located between teeth,
around old fillings, and large cavities that need to be prepared
for a crown. In addition, lasers cannot be used to remove
defective crowns or silver fillings, or prepare teeth for bridges.
Traditional drills may still be needed to shape the filling, adjust
the bite, and polish the filling even when a laser is used.
Lasers do not eliminate the need for anesthesia
Laser treatment are more expensive since the cost of the laser
is much higher than a dental drill. ( $39,000 and $45,000
compared to about $600 for a standard drill).
81. Laser diagnostic
• Laser Doppler Flowmetry
- To monitor pulpal and gingival blood flow
- To assess tooth vitality
• Laser Fluorescence for detection of caries
• Laser Doppler Vibrometry to measure tooth
mobility.
82. Laser Fluorescence (DIAGNOdent)
•
•
•
Detection for occlusal and smooth surface caries.
Uses diode laser light sources and a fiber-optic cable that
transmits the light to a hand-held probe with a fiber optic eye
in the tip.
Emitted fluorescence is collected at the probe tip, transmitted
through ascending fibers, and processed and presented on a
display window as an integer between 0 and 99.
•
•
fluorescence : carious state, > 20
Results in vitro studies indicated diagnodent
readings show a very good correlation with
histologic evidence of caries but not with the depth of the
lesion into dentin.
83. Hard tissue application
• Selective removal of caries -Nd:YAG,CO2 laser, Er:YAG,
excimer ,Waterlase
• Cavity preparation : Excimer,Nd:YAG,Er:YAG*,Waterlase
• Pit &Fissure sealant : Er;YAG
• Composite curing: Argon laser(488nm) (5 secs),
Bond strength and surface adhesion is ↑
84. • Bleaching : Argon, Nd:YAG and CO2
• Laser light is converted to heat as it strikes
the bleaching gel accelerate the oxidation of
peroxide
• Immediate result and more convenient
improved appearance
85. • Pulpal therapy
- time consuming and messy
laser amputed pulp stumps hemostasis,
bactericidal effects, surface coagulation.
- fiberoptic system ( fibers size 200µ), highly flexible and
introduced to the apex.
- Research with Nd:YAG and co2 laser has verified the
value of avoiding formacresol.
86. Pulp capping and pulpotomy
• CO2 laser is used because
– Arrest bleeding
– Disinfect dentinal exposure of 1sqmm size
– Success rate is 91% in younger group compared to 68%
where Ca(OH)2
– Pulpotomy has shown higher success rate
Excimer, Ar, Nd:YAG, Er:YAG, Ho:YAg
• In 1996, Wilkerson et al evaluated the clinical, radiographic
and histologic effects of argon laser on vital pulpotomy
and the results showed that all soft tissues remained
normal and all teeth exhibit normal mobility.
•Reparative dentin formation was noted histologically.
(J Clin Las Med and Surg,1996,14).
87. When a fistula is present
laser fiber is passed thru the fistula canal to the site of the
abscess formation.
•
disrupt the infection temporarily and reduce the symptoms
In 1985, Ebinara reported the effects of Nd:YAG laser on
the wound healing of amputated pulps and
reported better healing in pulps exposed
to laser than in controls in 1stweek and
facilitation of dentinal bridge formation in
5thand 12th postoperative weeks.
(J Conserv Dent,32,1989)
88. Root canal wall preparation by laser
• Straight and slightly curved canals
• The laser tip slide gently from the apical portion to the
coronal portion pressing the laser tip to the canal wall
under spray.
• When laser is unable to be inserted into the canals, t/t
should be carried out after usual root canal preparation
using reamers and files.
89. • Various studies have shown the smear layer was removed
completely and the dentinal tubules on the root canal wall
were opened using this technique.
• Rooney et al reported sterilization rates of 80%- 90%
whereas others reported 60% depending on the condition
of the root canals, type of laser, technique and application
parameters.
• Levy reported that and experimental Nd:YAG laser system
was more effective in cleaning and shaping root canals
than conventional hand instrumentation.( J Endod 1992 ;
18)S
90. • First used in Endodontics by Weichman and Johnson in
1971 who attempted to seal the apical foreman using a CO2
• Takeda et in 1999 used Er:YAG to disinfect canals. The
irradiated canals showed no smear layer and open tubules
in the apical and middle 3rd
• L. Bergams et in 2004 used Nd: YAG against Actinomyces
Naeslundi and S.Anginosus were discernable but only 99%
of E.facelis were killed, a complete sterilisation was not
achieved.
91.
92. ROOT CANAL FILLING BY GUTTA PERCHA AND LASER
•
•
GP is thought to be melted by laser heat energy.
Anic and matsumoto(1995) attempted to perform root
canal filing using sectioned GP segments and a pulsed
Nd:YAG laser
• This was shown to be possible by vertical condensation
method, but time required is too much.
• At present, the technique is not practical, requires further
research.
93. DESENSITIZATION OF HYPERSENSITIVY OF
DENTIN AND TEETH BY LASER STIMULATION
• Laser devices: semiconductor diode laser, pulsed Nd:YAG
laser, CO2 laser
• Procedure:
after drying the hypersensitive dentin, the laser tip is placed
in direct contact with the tooth surface, which is then
irradiated for a period of 30 secs – 3mins.
• Clinical assessment after a postoperative period of 4months,
73% of cases of slight cervical dentin hypersensitivity, 19% of
mild cases, and 14% cases of severe pain showed a reduction
in hypersensitivity.
94. • The mechanism of pain reduction by the laser stimulation
is thought to be clarified by electrophysiologic and laser
transmission studies.
indicates local changes around the dentin and the nerve
endings as well as changes in the central pulp neuron.
• Recently Gelskey et al reported that Nd:YAG laser reduced
thermal dentinal desensitivity by 58% and mechanical
stimulation by 61%.
95. limitation
• Special training and attention for
safety
• No single laser can perform all
desired dental application
• Expensive
96. Refrences
Laser in Dentistry, Leo J.Miserendino/Robert M.pick, 1995
Laser in dentistry: Dental clinic of North America Vol.44,no. 4 Oct. 2000
Naresh Thukral; Laser in General Dental practice: SOLEZE-Journal of Laser
Dentistry vol.1 no. 1 March 2007
Pankaj Chivte; Hazards of laser surgery: SOLEZE- Journal of Laser Dentistry Vol.
1 No. 1 March 2007
L. J. Walsh; The current status of low level laser therapy in dentistry: Australian
Dental Journal 1997;42:5
Aysegul: Clinical evaluation of Diagnodent in detection of occlusal caries in
children: Journal of Pediatric Dentistry 2006; 30 :4
Guy levy, cleaning and shaping the root canals with Nd:YAG laser beam: A
Comparative study,J Endod,18,1992.
97. • Chengfei zhang, Matsumoto, effects of co2 laser in treatment of
cervical dentinal hypersensitivity Endod ,24, 1998.
• Matsumoto, Khan Azman, effects of laser treatment on the root
canal of human teeth, Endod Dent Traumatol,13,1997
• LJ Walsh . The current status of laser in Dentistry. Australian
Dental Journal 2003 ; 48 : (3) 146-155
• Takeda . A comparative study of removal of smear layer using
three endodontic irrigants and two types of laser . IEJ 32; 32-39 :
1999.